Type-writing machine.



J. O. MOLAUGHLIN. 'TYPE WRITING MACHINE. APPLICATION FILED MAY 2, 190a.

Patented Nov. 24, 1908.

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A f/ornx UNIT STATES PATENT OFFICE.

JOHN C. McLAI IGHLIN, OF JERSEY CITY, NEW JERSEY, ASSIGNOR TO UNDERWOOD TYPE- WRITER COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

' TYPE- RITING MACHINE.

Specification of Letters. Patent.

Application filed May 2,1908. Serial No. 480,581.

Patented Nov. 24, 1908.

To all whom it may concern:

Be it known that I, JOHN C. MCLAUGH- LIN, a citizen of the United States, residing in Jersey City, in the county of Hudson and State of New Jersey, have invented certain new and useful Improvements in .Type- Writin Machines, of which the following is a speci cation.

This invention relates to means for controlling the revoluble platens of typewriting;

tent, a slight forward or backward rotation.

is often accidentally 1m arted to the platen during the writin of a inc, and the troubleis not discovered y the operator until after a number of characters or words have been writtenout of place on the paper. This ises ecially so when filling out stiflz' cards, w 'ch do not readilyconform to the curvature of the platen, and have a tendency to spring forward when fed around the same.

The main object of my invention is to provide simple, inexpensive and readily a plied and operated means to overcome. this.

objection;

It will be understood that the-usual cam lever for forcing the detent away from the line-space whee is all that is necessary for many purposes the platen being sufficiently immobile to permit writing on pa er without liability of accidental. rotatlon; whenever it is desired to hold the platen more firmly against rotation, I call into action an auxiliary lever, wh1ch is mounted upon the platen axle alongside ofthe detentreleasing lever; and this auxiliary lever serves to effect a powerful binding or braking action upon the platen shaft. For this purpose the auxiliary lever preferably ob-' tains a purchase'upon the pin carried by'the detent, so that the platen 1s bound-not only by said" auxiliarylever, but also by the aforesaid releasing lever, which it will be understood engagesthesame pin. In other words,

the auxiliary or braking lever is pivoted upon the platen axle, and has an arm providedwith a cam. to engage said pin upon the detent lever; and since the turning of the auxiliary lever tends to jam the pin towards the platen axle, and since the pin is supported against such movement by means' of the aforesaid releasing lever, it follows that the latter ispressed firmly against the platen axle to produce friction thereon, while the auxiliary lever is forced with about the same pressure in the opposite direction a ainst the platen axle, thereby making in e set two brakes to oppose the turning of the platen.

In the accompanying drawings, Figure l shows edge and side news of the usual detent-releasing lever. Fig. 2' presents a side and edge view of the novel braking lever. Fi 3.is a plan, partly in section, of a platen an platenframe of an Underwood typewriting machine, with my improvements applied thereto. Fig. 4' is an end elevation o the platen-controlling instrumentalities showing the partsin normal positions. Fig. 5 is a view similar to Fig. 4, but showing the detent released from the line space wheel, for ordinary work where it is desired to se- .cma'.- irregular spacing. Fig, 6 is a similar.

view but showing the brakin means applied, for diflicult work, as car s, etc.

/ The usual platen 1 is rotatably mounted b means of an axle 2 in the ends 3 of a. pla

ten frame, which also comprises a paper shelf 4. A notched line space wheel 5 is fixed upon the platen axle, normally engaged by a roll 6 of a spring detent 7. The usual lever 8, having a finger piece 9, is mounted to swing up upon the hub 10 of the line space Wheel 5, said lever having a cam-edge 11 to engage. a pin 12 up0n the detent 6, to force the same'a'way from the line space wheel, against the action of the spring 14, when it is desired to turn the platen irregular line spaces by the knob 15, as when writing on ruled paper; the cam 11 being usuallyformed to lock the detent mechanically out of use, as at Fig. 5. A two-armed auxiliary lever 16 is also fulcrunied on the platen axle at the side of the lever 8, one arm having a finger piece 17, and the other arm having a cam-slot 18, to enga e the. same is engaged by there ease lever 8.

After the platen is released from thcdetent, as at Fig. 5, a forward pull on the finger iece 17 of lever 16, causes the cam-edge 19 pin 12 that m the slot 18 to ride up over the pin 12, the

' space wheel, a spring detent therefor, and a cam edge 19 being a little eccentric to the platen axle, or shaped to wedge or draw said lever backward by reason of its purchase on.

the pin 12. The lever re-acts on the platen axle (or on the hub 10), and frictionally opposes its rotation. At the same time it will be understood that a forward thrust is imparted to the detent-releasing lever 8, also causing said lever to bind on the platen axle, to augment the frictional opposition to the rotation of the platen. In other words, the arm 16 forces the pin 12 and hence the lever Sagainst the hub 10, so that a two-fold braking effect is secured.

It will be seen at Fig. 6 that the inclination of the cam 19 is so slight that the auxiliary lever 16 is mechanically held or locked in effective position, so that both hands of the operator are free to be used in manipulating the keys; the friction between the lever 16 and the hub 10 and-between the caln 19 and the pin 12 being sufficient to prevent said lever from resuming the normal Fig. 5 position. I

Having thus described my invention, I claim: I 1. In a typewriting machine, the combination with a revoluble platen having a linedevice to release said detent and hold it mechanically away from the line-space wheel, of an auxiliar device operable at will for causing said etent-releasing device to oppose friction to the revolution of the platen.

2. In a typewriting machine, the combination with a revoluble platen having a linespace wheel, a spring detent tlterefor, and a device to release said detent and hold it mechanically away from the line space wheel, of an auxiliary device operable at will for causing said detent-releasing device to opsaid releasing device against the'axle, thus to secure a double braking effect upon the axle or the platen.

4. In a typewriting machine, the combinetion with a revoluble platen, of a braking device mounted upon the platen and engaging a' relatively fixed'partto tend to draw said fixed part towards the axis of the platen for the purpose of binding the axle.

5. In a typewriting machine, the combination with a revoluble platen having an axle,

of a braking device mounted upon the platen and engaging a relatively fixed part to tend to draw said fixed part towards the axle of the platen for the purpose of binding the axle, the parts constructed to detain the braking device mechanically in elfective position.

6. In a typewriting machine, the combination with a revoluble platen having an axle or hub, of a lever fulcrumed upon the axle or hub and having a cam, and a relatively fixed device engaged'by said cam to crowd and bind against the platen axle and oppose the revolution of the platen.

7 In a typewriting machine, the combination with a revoluble platen having an axle or hub, of a lever fulcrumed upon the axle or hub and having a cam, a relatively fixed device engaged by said cam to crowd and bind the platen axle and oppose the revolution of the platen; and means independent of said lever to release the platen from the control of the spring detent.

8. In a typewriting machine, the combination with a revoluble platen, of braking means therefor including two independently operable members, and means to cause them to cooperate to press transversely against the platen in opposite directions to prevent accidental rotation of the platen.

9. In a typewriting machine, the combination with a revoluble platen, of braking means therefor including twd independently operable members, and means to cause them to cooperate to press transversely against the platen in opposite directions to prevent accidental rotation of the platen; and means operable by one of said members to release the platen from the control of the spring detent.

10. In a typewriting machine, the combination with a platen and a line-space wheel connected thereto and having a hub, of two independently operable levers upon said hub, one lever having means to release the ratchet wheel from the control of the detent, and the other lever having means to effect a binding action upon said hub.

11. In a typewriting machine, the combination with aplaten and a line-space wheel connected thereto and having a hub, of two independently operable levers upon said hub, one lever having means to release the ratchet wheelfrom the control of the detent, and the other lever having means to cause both levers to bind upon said hub and in different directions. I

12. In a typewriting machine provided with a platen having an axle, the combination with a line-space wheel upon said axle, of a spring detent engaging said wheel, a detent-releasing lever mounted to turn upon said axle, and an auxiliary device operable at will independently of the releasing lever, to co-act with the detent-releasing lever to a create a binding action on the platen axle for preventing accidentalrotation of the platen. I

13. In a ty ewriting machine provided with a platen rame and a platen having an axle journaled int'he platenframe, the combinationwith a line-space wheel upon said axle, a spring detent engaging said wheel, andmeans mounted to turn upon the axle and operable to force and hold the detent away from the wheel, ogE-an independently.

operable auxiliary lever fulcrumed upon said axle and engaging means to draw said lever against the platen axle.

14. In a typewriting machine provided with a platen having an axle and a platenframe in which the axle is journaled, the combination with a line-space wheel-upon said axle, of a spring detentfor-said wheel,

said detent having a pin,"a lever mounted to turn upon the axle to'force and hold the detent roll away from the wheel, an auxiliary lever fulcrumed upon saidaxle andhaving a cam to engage said pin, to cause the auxiliary lever to bind on theaxle to hold the platen against accidental rotation.

'15 In a typewriting machine provided with a platen having an axle and a' laten frame in which the axleis journale the combination with a line-space wheel upon said axle, of a spring detent having a roll to engage said wheel, and having also a projection, a lever mounted upon the axle to force and hold the detent roll away from the wheel, an auxiliary lever fulcrumed upon said, axle, and having a cam to engage said projection, so that a pull on the auxiliary lever causes the cam edge to ride up over theprojection,

and simultaneously thrust thereleasing lever against the axle, whereby both levers hold the platen against accidental rotation.

"to draw the'auxiliary lever against the axle 16. In a typewriti'ng machine provided wheel, and means to, apply pressure upon the platen axle opposite. to the pressure applied by said detent-releasing lever, to create a double binding action onthe laten axle to hold the platen against acci ental rotation.

JOHN MOLAUGHLIN.

Witnesses:

, Jon 0. Snnma'r,

. K. FRANKF RT. 

